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Increase the Reliability of Your Revit Model with Better Modeling Habits

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As with many things in Revit, there are a number of methods you could use to approach the same modeling task. This article will provide insight into various modeling conditions and ways you can add value to the model, workflows, and ultimately your project. We want to also recognize that because there are so many ways to accomplish things in Revit, we don’t pretend to know every good and perfect way. From experience, we have attempted to provide a meaningful approach to discussing some of the issues and ways we have found they can be solved.

“Just Because You Can, Doesn’t Mean You Should”

While we are modeling more and more to satisfy various project needs which may include things like model as a deliverable, 3D design coordination and clash detection, augmented and virtual reality, etc., there are certainly cases/conditions where you should consider if it’s really necessary to model the object at a high level of detail. It is advised that you spend time with your project team to identify and develop, at a minimum, a level of development/detail matrix and BIM uses document to help inform everyone on the team of the expected outcomes. At Perkins+Will, we highly encourage the use of BIM Execution Planning to help identify these things.

Choose the Right Modeling Method/Workflow for Your Task/Project

When it is necessary to go into additional detail in the modeling exercise or workflow, take a few extra minutes and weigh the pros and cons of each method and pick the one best suited for your project.

Is there already a known best practice?

In some cases, the choice may be obvious, as it may be a known best practice or workflow. Look to and learn from other people that may have already tried what you are doing. That said, challenge what is “known.” New versions of Revit often change what was previously known as a best practice, giving us better ways to creatively solve problems.

What is the expertise of the project team?

Can the team that is going to be working on the project manage the effort? If not, an elevated model/workflow may cause more harm later than it does good. You may consider doing a targeted training to help elevate the skillset of the staff.

Are you prepared and able to support the additional effort?

If you are proposing additional modeling or more advanced workflows, you should plan to be available to troubleshoot problems/challenges as they arise. For example, some of our projects heavily use Model groups to manage repetition, and as you likely know, groups can be very finicky when best practices are not followed. Inevitably, someone on the team will make a mistake, which can cause downstream workflow issues. When those issues arise, someone should have the expertise and knowledge to solve the problem and train the team member(s) what to do in the future, instead of the team deciding they “hate groups.” Certainly, groups have their pros and cons, but as the example in this case, when they are used in the right circumstances and in the right ways, they can work well and add value to the coordination and change management of your project.

Modeling and Detailing

The model/detail relationship in Revit is, when done thoughtfully, one of the best ways you can increase the value and reliability of your project models. The techniques we are going to describe in this section are commonly referred to as “Hybrid Detailing.” To start, we want to provide a few thoughts/tips for your consideration.

Model only — top and bottom of exterior wall at entry.
Model only—top and bottom of exterior wall at entry.

Designers often have very negative feelings toward certain workflows often because they had a very poor experience on a project and vowed “to never do it again.” This is very unfortunate and can be solved when teams are properly trained and mentored in those more advanced methods/processes.

Model and detail items/annotations. Magenta items are added components.

Model and detail items/annotations. Magenta items are added components.
Model and detail items/annotations. Magenta items are added components.

Drafting Views vs. Live Model Views

One of the biggest decisions a modeler has to make on a project is whether he/she will use the model to base the details or simply draw in drafting views. There are certainly pros and cons to both methods. Here are some general tips to follow that we believe add the most value and reliability to the model.

Use the model whenever possible, especially in atypical and/or project specific details.

• Value is less risk and better execution of the design intent.

• Challenge is learning curve for project teams and producing detail item families that “embellish” the model, without adversely covering it.

• Drafting views do not pick up changes to items like linked model updates, grid location changes, etc.

• Drafting views are still very useful for things like typical details. They are also very easy to transfer between projects.

• If you have a detail library of drafting views, consider copying and pasting relevant notes, components, etc., to a live view in your project. This saves time and effort in embellishing the live view but also gains the benefit of the drafting view as a starting point in a library.

When using the model as the basis of the detail, do not turn off the model.

All too often, we find staff that started out with good intensions, but in the end, could not get the drawing the way they wanted so they turned off parts of the model or the entire model. Here are a few tips to help with that.

Use cut line styles in Visibility/Graphics Overrides—This is a little gem in the Visibility/Graphics Overrides dialog box that I find most people seem to completely ignore. When I found it, it was one part of the process of creating a better hybrid detail.

Cut line styles off (left); cut line styles on (right).
Cut line styles off (left); cut line styles on (right).

Notice the subtle but important difference, especially around the mortar joint repeating detail component. Be sure to play with the Core Layer Clean-up drop down, along with the Common Edge Style subcategory for system families like walls, roofs, floors, and ceilings. The one challenge with this method is that you will need a filter for floors to bring the structural layer line weight back to where it needs to be.

Use Detail custom component families that only mask parts of the model—For example, use a special mortar joint family that masks out the line work of the model, instead of covering the entire thing.

Repeating detail component of masonry mortar joint only.
Repeating detail component of masonry mortar joint only, with masking regions at each side to hide the vertical lines of the brick layer properly.

Unlock the bottom/top of portions of the wall assembly—This is a fantastic way to extend only portions of the wall assembly up or down, such as a brick ledge or exterior material needing to stop short at a soffit. Unlocked layers must be adjacent. This solves several problems with drawing graphics and model completeness.

Set the preview to Section, click Modify, select the bottom line of a layer, and click the padlock to lock/unlock the layer.
Set the preview to Section, click Modify, select the bottom line of a layer, and click the padlock to lock/unlock the layer.

Coordinate and get corrected models from consultants—For architects, this is often true with the structural consultant with regard to exterior detailing and the MEP consultant with reflected ceiling plans.

Instead of your first response being to just turn off the model, consider leaving it on so you can see it clearly incorrect. Screenshot the issue, and send it to other parties for review and correction. This may seem like an obvious part of the coordination process, but unfortunately, designers often get hung up on the drawing looking perfect in the short term, so they turn off the model and then forget to turn it back on.

We have found that leaving the incorrect model on often allows mistakes to be caught, especially in later phases of the design process and is a constant reminder to the entire team of issues that need to be resolved. If the linked models are turned off, it will be much less evident and you lose the benefit of using BIM to help identify those issues when you bring the components in from the other disciplines.

Utilize filters and the line work tool to accomplish graphic overrides—There are so many things filters can be used for. With regard to modeling and detailing, filters are a fantastic way to reduce or even eliminate the need to override linked models to Custom in Visibility Graphics. I have found and seen so many issues and inconsistent graphics when staff have to set their graphic overrides per model, in multiple places. And while there is certainly a time and place to use custom visibility graphics overrides at the model level, it is much less necessary than what I see done by most Revit users.

For example, in many cases, I find staff override the linked model to Custom just to turn off its level and grids. This is usually the “gateway” to it staying this way the rest of the project. To handle levels and grids, use a filter. If your company has a naming standard, it’s very easy to use a filter to get all grids/levels that don’t contain, for example, a company prefix. Then turn them off.

Screenshot

Have you or your staff ever been in a situation where you are trying to override objects from a linked model, and unable to do so from the host view settings? So, naturally, you can fix this. Just set the model override to custom and it all works! Ugh, I cringe at this, because a simple filter would solve this problem. The issue is that your model doesn’t contain all the subcategories that are in the linked model, and any objects assigned to those subcategories can’t be overridden by the host view graphics overrides. But a filter, even when not technically filtering anything within the category, automatically overrides all aspects of the category, including subcategories!

Wall Sweeps and Reveals

Wall articulation is common to the design process and there are several tools in Revit to accomplish this. Here are a few tips to be aware of/follow when modeling this content.

Pick side matters—When placing sweeps and reveals, it is important to realize that the pick side of the wall matters. This can be the cause of sweeps not cleaning up properly and is so simple to avoid.

Consider stacked walls for sweeps and reveals that are generally continuous—There is an incredible amount of opportunity with stacked walls and I highly encourage their use, especially with exterior modeling of vertically compound wall assemblies. While we don’t have time to talk about all of the various benefits of stacked walls, it’s pertinent to mention their use with regard to hybrid detailing.

For example, when trying to set corbel masonry like brick or cast stone, setting the brick back with a revel cuts the face of the wall out, but doesn’t add the same dimension in the air gap space of the wall. While it may seem minor, I imagine countless hours of people that want to use a live model/hybrid detail approach, faking in the masonry units rear face when it can be avoided entirely by doing the masonry unit insets/outsets with stacked walls.

Embed detail components in profiles—This is a game changer for detailing, especially exterior detailing. When done appropriately, you can embed parametric detail components into parametric profiles that allow your staff to not have to embellish the same things over and over again. There are numerous examples of this, but a few include cast stone window head and sills, parapet copings, and curtain wall mullions. You might ask, “So what’s the point, I thought this was about better modeling, not detailing.” Well, when you create families that embed the detailing into the model, you create an avenue for staff to spend less time detailing and more time modeling. If you start creating these sorts of families and workflows for your firm, you will increase the time your staff has to produce the BIM, as well as increase coordination and reduce risk exposure of your projects.

Dynamic To-Do List

Have you ever been given a task and while attempting to tackle it, you see other issues in the model? Ever make a decision when modeling and wish you could flag it for follow up later? This Dynamic To-Do List allows you to keep a live list of action items within the Revit project. Via a symbol family and a Note Block schedule, your dreams are within reach!

I have one symbol family with two types, Low Priority and High Priority. In addition, I have a slew of instance properties: responsible, description, comments, and complete (yes/no).

As you place one of these families, you can fill in a brief description and leave it at that. Now or later, you can add additional information via comments. Or even assign the task to a colleague. Once the task is completed, one checks the box (highlighting the task to suggest it was done). A project manager, for example, can follow up and delete the task once confident it was addressed.

Screenshot

Create a couple of Note Block schedules (as shown above). I’d encourage making this screen your open/close screen. Staff will open the project and see what is outstanding and critical.

What about printing/exporting? Place a yes/no visibility parameter within the family. Assign it to all geometry. Shy of printing/exporting to CAD, uncheck the parameter. I’d encourage you to create a schedule (as shown above), and just uncheck or check it there.

Code Compliance

As noted in the image below, Perkins+Will automates occupancy calculations (tabularly and via tags in plan), plumbing fixture calculations, path of travel, and (for a little sizzle) we add a color scheme. All this is possible via a new occupancy area scheme, two key schedules (reflective of IBC), and Dynamo script.

Screenshot

Occupancy Area Scheme

Considering all the new parameters and key schedules, it is best to create a new area scheme. Once the scheme is created, create area plans looking at said scheme for each floor.

Key Schedules

Give yourself some time on this next effort. You will want to create two key schedules looking at this new area scheme: Function of Space and Use Classification Key.

Screenshot

As suggested in the image above, you will want to create a parameter for every line from the building code, driven by each key. Then insert data rows for every condition. Populate each parameter per the code. This way, when someone selects an area and answers both key questions, all the data reflective of the code will populate.

Screenshot

Josh Moore is a design applications manager at Perkins+Will, where he is responsible for the development, training, and support of digital design tools. He is regularly engaged by design teams and leadership for his expertise in executing successful BIM projects. While at Perkins+Will, his efforts have focused on implementing and improving Revit content and workflows and providing and managing automation solutions. He is passionate about understanding the process of architecture and translating it into practical and successful uses of design technology.

Justin Benjamin has been the design applications manager in Perkins+Will Washington, DC, office for over four years. He has an additional eight years of experience in the architecture and engineering industry (combining his design studio experience with design applications expertise). He has been an Autodesk Revit Architecture Certified Professional and guided project teams through their required applications in all phases from programming through construction. Justin also has extensive expertise in BIM and computer-aided facility management systems.

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Many designers often feel it can be difficult to create models that accurately express their design intents, often trying to "beat Revit software into submission." This often leads to poor modeling habits, and in some cases, a complete lack of necessary model geometry, causing coordination issues. In this course, we'll discuss the common challenges encountered when modeling various types of building elements, and we'll cover some tips and tricks for overcoming them. We'll find some solutions are...

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